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          <h1>Node.js v14.19.1 documentation</h1>
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      <details id="toc" open><summary>Table of contents</summary><ul>
<li><a href="#cli_command_line_options">Command-line options</a>
<ul>
<li><a href="#cli_synopsis">Synopsis</a></li>
<li><a href="#cli_options">Options</a>
<ul>
<li><a href="#cli"><code>-</code></a></li>
<li><a href="#cli_1"><code>--</code></a></li>
<li><a href="#cli_abort_on_uncaught_exception"><code>--abort-on-uncaught-exception</code></a></li>
<li><a href="#cli_completion_bash"><code>--completion-bash</code></a></li>
<li><span class="stability_1"><a href="#cli_c_condition_conditions_condition"><code>-C=condition</code>, <code>--conditions=condition</code></a></span></li>
<li><span class="stability_1"><a href="#cli_cpu_prof"><code>--cpu-prof</code></a></span></li>
<li><span class="stability_1"><a href="#cli_cpu_prof_dir"><code>--cpu-prof-dir</code></a></span></li>
<li><span class="stability_1"><a href="#cli_cpu_prof_interval"><code>--cpu-prof-interval</code></a></span></li>
<li><span class="stability_1"><a href="#cli_cpu_prof_name"><code>--cpu-prof-name</code></a></span></li>
<li><a href="#cli_diagnostic_dir_directory"><code>--diagnostic-dir=directory</code></a></li>
<li><a href="#cli_disable_proto_mode"><code>--disable-proto=mode</code></a></li>
<li><a href="#cli_disallow_code_generation_from_strings"><code>--disallow-code-generation-from-strings</code></a></li>
<li><a href="#cli_dns_result_order_order"><code>--dns-result-order=order</code></a></li>
<li><a href="#cli_enable_fips"><code>--enable-fips</code></a></li>
<li><a href="#cli_enable_source_maps"><code>--enable-source-maps</code></a></li>
<li><a href="#cli_experimental_abortcontroller"><code>--experimental-abortcontroller</code></a></li>
<li><a href="#cli_experimental_import_meta_resolve"><code>--experimental-import-meta-resolve</code></a></li>
<li><a href="#cli_experimental_json_modules"><code>--experimental-json-modules</code></a></li>
<li><a href="#cli_experimental_loader_module"><code>--experimental-loader=module</code></a></li>
<li><a href="#cli_experimental_modules"><code>--experimental-modules</code></a></li>
<li><a href="#cli_experimental_policy"><code>--experimental-policy</code></a></li>
<li><a href="#cli_experimental_repl_await"><code>--experimental-repl-await</code></a></li>
<li><a href="#cli_experimental_specifier_resolution_mode"><code>--experimental-specifier-resolution=mode</code></a></li>
<li><a href="#cli_experimental_vm_modules"><code>--experimental-vm-modules</code></a></li>
<li><a href="#cli_experimental_wasi_unstable_preview1"><code>--experimental-wasi-unstable-preview1</code></a></li>
<li><a href="#cli_experimental_wasm_modules"><code>--experimental-wasm-modules</code></a></li>
<li><a href="#cli_force_context_aware"><code>--force-context-aware</code></a></li>
<li><a href="#cli_force_fips"><code>--force-fips</code></a></li>
<li><span class="stability_1"><a href="#cli_frozen_intrinsics"><code>--frozen-intrinsics</code></a></span></li>
<li><span class="stability_1"><a href="#cli_heapsnapshot_near_heap_limit_max_count"><code>--heapsnapshot-near-heap-limit=max_count</code></a></span></li>
<li><a href="#cli_heapsnapshot_signal_signal"><code>--heapsnapshot-signal=signal</code></a></li>
<li><span class="stability_1"><a href="#cli_heap_prof"><code>--heap-prof</code></a></span></li>
<li><span class="stability_1"><a href="#cli_heap_prof_dir"><code>--heap-prof-dir</code></a></span></li>
<li><span class="stability_1"><a href="#cli_heap_prof_interval"><code>--heap-prof-interval</code></a></span></li>
<li><span class="stability_1"><a href="#cli_heap_prof_name"><code>--heap-prof-name</code></a></span></li>
<li><a href="#cli_icu_data_dir_file"><code>--icu-data-dir=file</code></a></li>
<li><a href="#cli_input_type_type"><code>--input-type=type</code></a></li>
<li><a href="#cli_inspect_brk_host_port"><code>--inspect-brk[=[host:]port]</code></a></li>
<li><a href="#cli_inspect_port_host_port"><code>--inspect-port=[host:]port</code></a></li>
<li><a href="#cli_inspect_host_port"><code>--inspect[=[host:]port]</code></a>
<ul>
<li><a href="#cli_warning_binding_inspector_to_a_public_ip_port_combination_is_insecure">Warning: binding inspector to a public IP:port combination is insecure</a></li>
</ul>
</li>
<li><a href="#cli_inspect_publish_uid_stderr_http"><code>--inspect-publish-uid=stderr,http</code></a></li>
<li><a href="#cli_insecure_http_parser"><code>--insecure-http-parser</code></a></li>
<li><a href="#cli_jitless"><code>--jitless</code></a></li>
<li><a href="#cli_max_http_header_size_size"><code>--max-http-header-size=size</code></a></li>
<li><a href="#cli_napi_modules"><code>--napi-modules</code></a></li>
<li><a href="#cli_no_addons"><code>--no-addons</code></a></li>
<li><a href="#cli_no_deprecation"><code>--no-deprecation</code></a></li>
<li><a href="#cli_no_force_async_hooks_checks"><code>--no-force-async-hooks-checks</code></a></li>
<li><a href="#cli_no_warnings"><code>--no-warnings</code></a></li>
<li><a href="#cli_node_memory_debug"><code>--node-memory-debug</code></a></li>
<li><a href="#cli_openssl_config_file"><code>--openssl-config=file</code></a></li>
<li><a href="#cli_pending_deprecation"><code>--pending-deprecation</code></a></li>
<li><span class="stability_1"><a href="#cli_policy_integrity_sri"><code>--policy-integrity=sri</code></a></span></li>
<li><a href="#cli_preserve_symlinks"><code>--preserve-symlinks</code></a></li>
<li><a href="#cli_preserve_symlinks_main"><code>--preserve-symlinks-main</code></a></li>
<li><a href="#cli_prof"><code>--prof</code></a></li>
<li><a href="#cli_prof_process"><code>--prof-process</code></a></li>
<li><a href="#cli_redirect_warnings_file"><code>--redirect-warnings=file</code></a></li>
<li><a href="#cli_report_compact"><code>--report-compact</code></a></li>
<li><a href="#cli_report_dir_directory_report_directory_directory"><code>--report-dir=directory</code>, <code>report-directory=directory</code></a></li>
<li><a href="#cli_report_filename_filename"><code>--report-filename=filename</code></a></li>
<li><a href="#cli_report_on_fatalerror"><code>--report-on-fatalerror</code></a></li>
<li><a href="#cli_report_on_signal"><code>--report-on-signal</code></a></li>
<li><a href="#cli_report_signal_signal"><code>--report-signal=signal</code></a></li>
<li><a href="#cli_report_uncaught_exception"><code>--report-uncaught-exception</code></a></li>
<li><a href="#cli_throw_deprecation"><code>--throw-deprecation</code></a></li>
<li><a href="#cli_title_title"><code>--title=title</code></a></li>
<li><a href="#cli_tls_cipher_list_list"><code>--tls-cipher-list=list</code></a></li>
<li><a href="#cli_tls_keylog_file"><code>--tls-keylog=file</code></a></li>
<li><a href="#cli_tls_max_v1_2"><code>--tls-max-v1.2</code></a></li>
<li><a href="#cli_tls_max_v1_3"><code>--tls-max-v1.3</code></a></li>
<li><a href="#cli_tls_min_v1_0"><code>--tls-min-v1.0</code></a></li>
<li><a href="#cli_tls_min_v1_1"><code>--tls-min-v1.1</code></a></li>
<li><a href="#cli_tls_min_v1_2"><code>--tls-min-v1.2</code></a></li>
<li><a href="#cli_tls_min_v1_3"><code>--tls-min-v1.3</code></a></li>
<li><a href="#cli_trace_atomics_wait"><code>--trace-atomics-wait</code></a></li>
<li><a href="#cli_trace_deprecation"><code>--trace-deprecation</code></a></li>
<li><a href="#cli_trace_event_categories"><code>--trace-event-categories</code></a></li>
<li><a href="#cli_trace_event_file_pattern"><code>--trace-event-file-pattern</code></a></li>
<li><a href="#cli_trace_events_enabled"><code>--trace-events-enabled</code></a></li>
<li><a href="#cli_trace_exit"><code>--trace-exit</code></a></li>
<li><a href="#cli_trace_sigint"><code>--trace-sigint</code></a></li>
<li><a href="#cli_trace_sync_io"><code>--trace-sync-io</code></a></li>
<li><a href="#cli_trace_tls"><code>--trace-tls</code></a></li>
<li><a href="#cli_trace_uncaught"><code>--trace-uncaught</code></a></li>
<li><a href="#cli_trace_warnings"><code>--trace-warnings</code></a></li>
<li><a href="#cli_track_heap_objects"><code>--track-heap-objects</code></a></li>
<li><a href="#cli_unhandled_rejections_mode"><code>--unhandled-rejections=mode</code></a></li>
<li><a href="#cli_use_bundled_ca_use_openssl_ca"><code>--use-bundled-ca</code>, <code>--use-openssl-ca</code></a></li>
<li><a href="#cli_use_largepages_mode"><code>--use-largepages=mode</code></a></li>
<li><a href="#cli_v8_options"><code>--v8-options</code></a></li>
<li><a href="#cli_v8_pool_size_num"><code>--v8-pool-size=num</code></a></li>
<li><a href="#cli_zero_fill_buffers"><code>--zero-fill-buffers</code></a></li>
<li><a href="#cli_c_check"><code>-c</code>, <code>--check</code></a></li>
<li><a href="#cli_e_eval_script"><code>-e</code>, <code>--eval "script"</code></a></li>
<li><a href="#cli_h_help"><code>-h</code>, <code>--help</code></a></li>
<li><a href="#cli_i_interactive"><code>-i</code>, <code>--interactive</code></a></li>
<li><a href="#cli_p_print_script"><code>-p</code>, <code>--print "script"</code></a></li>
<li><a href="#cli_r_require_module"><code>-r</code>, <code>--require module</code></a></li>
<li><a href="#cli_v_version"><code>-v</code>, <code>--version</code></a></li>
</ul>
</li>
<li><a href="#cli_environment_variables">Environment variables</a>
<ul>
<li><a href="#cli_force_color_1_2_3"><code>FORCE_COLOR=[1, 2, 3]</code></a></li>
<li><a href="#cli_node_debug_module"><code>NODE_DEBUG=module[,…]</code></a></li>
<li><a href="#cli_node_debug_native_module"><code>NODE_DEBUG_NATIVE=module[,…]</code></a></li>
<li><a href="#cli_node_disable_colors_1"><code>NODE_DISABLE_COLORS=1</code></a></li>
<li><a href="#cli_node_extra_ca_certs_file"><code>NODE_EXTRA_CA_CERTS=file</code></a></li>
<li><a href="#cli_node_icu_data_file"><code>NODE_ICU_DATA=file</code></a></li>
<li><a href="#cli_node_no_warnings_1"><code>NODE_NO_WARNINGS=1</code></a></li>
<li><a href="#cli_node_options_options"><code>NODE_OPTIONS=options...</code></a></li>
<li><a href="#cli_node_path_path"><code>NODE_PATH=path[:…]</code></a></li>
<li><a href="#cli_node_pending_deprecation_1"><code>NODE_PENDING_DEPRECATION=1</code></a></li>
<li><a href="#cli_node_pending_pipe_instances_instances"><code>NODE_PENDING_PIPE_INSTANCES=instances</code></a></li>
<li><a href="#cli_node_preserve_symlinks_1"><code>NODE_PRESERVE_SYMLINKS=1</code></a></li>
<li><a href="#cli_node_redirect_warnings_file"><code>NODE_REDIRECT_WARNINGS=file</code></a></li>
<li><a href="#cli_node_repl_history_file"><code>NODE_REPL_HISTORY=file</code></a></li>
<li><a href="#cli_node_repl_external_module_file"><code>NODE_REPL_EXTERNAL_MODULE=file</code></a></li>
<li><a href="#cli_node_skip_platform_check_value"><code>NODE_SKIP_PLATFORM_CHECK=value</code></a></li>
<li><a href="#cli_node_tls_reject_unauthorized_value"><code>NODE_TLS_REJECT_UNAUTHORIZED=value</code></a></li>
<li><a href="#cli_node_v8_coverage_dir"><code>NODE_V8_COVERAGE=dir</code></a>
<ul>
<li><a href="#cli_coverage_output">Coverage output</a></li>
<li><span class="stability_1"><a href="#cli_source_map_cache">Source map cache</a></span></li>
</ul>
</li>
<li><a href="#cli_no_color_any"><code>NO_COLOR=&#x3C;any></code></a></li>
<li><a href="#cli_openssl_conf_file"><code>OPENSSL_CONF=file</code></a></li>
<li><a href="#cli_ssl_cert_dir_dir"><code>SSL_CERT_DIR=dir</code></a></li>
<li><a href="#cli_ssl_cert_file_file"><code>SSL_CERT_FILE=file</code></a></li>
<li><a href="#cli_uv_threadpool_size_size"><code>UV_THREADPOOL_SIZE=size</code></a></li>
</ul>
</li>
<li><a href="#cli_useful_v8_options">Useful V8 options</a>
<ul>
<li><a href="#cli_max_old_space_size_size_in_megabytes"><code>--max-old-space-size=SIZE</code> (in megabytes)</a></li>
</ul>
</li>
</ul>
</li>
</ul></details>

      <div id="apicontent">
        <h2>Command-line options<span><a class="mark" href="#cli_command_line_options" id="cli_command_line_options">#</a></span></h2>


<p>Node.js comes with a variety of CLI options. These options expose built-in
debugging, multiple ways to execute scripts, and other helpful runtime options.</p>
<p>To view this documentation as a manual page in a terminal, run <code>man node</code>.</p>
<section><h3>Synopsis<span><a class="mark" href="#cli_synopsis" id="cli_synopsis">#</a></span></h3>
<p><code>node [options] [V8 options] [script.js | -e "script" | -] [--] [arguments]</code></p>
<p><code>node inspect [script.js | -e "script" | &#x3C;host>:&#x3C;port>] …</code></p>
<p><code>node --v8-options</code></p>
<p>Execute without arguments to start the <a href="repl.html">REPL</a>.</p>
<p>For more info about <code>node inspect</code>, see the <a href="debugger.html">debugger</a> documentation.</p>
</section><section><h3>Options<span><a class="mark" href="#cli_options" id="cli_options">#</a></span></h3>
<div class="api_metadata">
<details class="changelog"><summary>History</summary>
<table>
<tbody><tr><th>Version</th><th>Changes</th></tr>
<tr><td>v10.12.0</td>
<td><p>Underscores instead of dashes are now allowed for Node.js options as well, in addition to V8 options.</p></td></tr>
</tbody></table>
</details>
</div>
<p>All options, including V8 options, allow words to be separated by both
dashes (<code>-</code>) or underscores (<code>_</code>). For example, <code>--pending-deprecation</code> is
equivalent to <code>--pending_deprecation</code>.</p>
<p>If an option that takes a single value (such as <code>--max-http-header-size</code>) is
passed more than once, then the last passed value is used. Options from the
command line take precedence over options passed through the <a href="#cli_node_options_options"><code>NODE_OPTIONS</code></a>
environment variable.</p>
<h4><code>-</code><span><a class="mark" href="#cli" id="cli">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v8.0.0</span>
</div>
<p>Alias for stdin. Analogous to the use of <code>-</code> in other command-line utilities,
meaning that the script is read from stdin, and the rest of the options
are passed to that script.</p>
<h4><code>--</code><span><a class="mark" href="#cli_1" id="cli_1">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v6.11.0</span>
</div>
<p>Indicate the end of node options. Pass the rest of the arguments to the script.
If no script filename or eval/print script is supplied prior to this, then
the next argument is used as a script filename.</p>
<h4><code>--abort-on-uncaught-exception</code><span><a class="mark" href="#cli_abort_on_uncaught_exception" id="cli_abort_on_uncaught_exception">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v0.10.8</span>
</div>
<p>Aborting instead of exiting causes a core file to be generated for post-mortem
analysis using a debugger (such as <code>lldb</code>, <code>gdb</code>, and <code>mdb</code>).</p>
<p>If this flag is passed, the behavior can still be set to not abort through
<a href="process.html#process_process_setuncaughtexceptioncapturecallback_fn"><code>process.setUncaughtExceptionCaptureCallback()</code></a> (and through usage of the
<code>domain</code> module that uses it).</p>
<h4><code>--completion-bash</code><span><a class="mark" href="#cli_completion_bash" id="cli_completion_bash">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v10.12.0</span>
</div>
<p>Print source-able bash completion script for Node.js.</p>
<pre><code class="language-console"><span class="hljs-meta">$ </span><span class="language-bash">node --completion-bash > node_bash_completion</span>
<span class="hljs-meta">$ </span><span class="language-bash"><span class="hljs-built_in">source</span> node_bash_completion</span></code></pre>
<h4><code>-C=condition</code>, <code>--conditions=condition</code><span><a class="mark" href="#cli_c_condition_conditions_condition" id="cli_c_condition_conditions_condition">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v14.9.0</span>
</div>
<p></p><div class="api_stability api_stability_1"><a href="documentation.html#documentation_stability_index">Stability: 1</a> - Experimental</div><p></p>
<p>Enable experimental support for custom <a href="packages.html#packages_conditional_exports">conditional exports</a> resolution
conditions.</p>
<p>Any number of custom string condition names are permitted.</p>
<p>The default Node.js conditions of <code>"node"</code>, <code>"default"</code>, <code>"import"</code>, and
<code>"require"</code> will always apply as defined.</p>
<p>For example, to run a module with "development" resolutions:</p>
<pre><code class="language-console"><span class="hljs-meta">$ </span><span class="language-bash">node -C=development app.js</span></code></pre>
<h4><code>--cpu-prof</code><span><a class="mark" href="#cli_cpu_prof" id="cli_cpu_prof">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v12.0.0</span>
</div>
<p></p><div class="api_stability api_stability_1"><a href="documentation.html#documentation_stability_index">Stability: 1</a> - Experimental</div><p></p>
<p>Starts the V8 CPU profiler on start up, and writes the CPU profile to disk
before exit.</p>
<p>If <code>--cpu-prof-dir</code> is not specified, the generated profile is placed
in the current working directory.</p>
<p>If <code>--cpu-prof-name</code> is not specified, the generated profile is
named <code>CPU.${yyyymmdd}.${hhmmss}.${pid}.${tid}.${seq}.cpuprofile</code>.</p>
<pre><code class="language-console"><span class="hljs-meta">$ </span><span class="language-bash">node --cpu-prof index.js</span>
<span class="hljs-meta">$ </span><span class="language-bash">ls *.cpuprofile</span>
CPU.20190409.202950.15293.0.0.cpuprofile</code></pre>
<h4><code>--cpu-prof-dir</code><span><a class="mark" href="#cli_cpu_prof_dir" id="cli_cpu_prof_dir">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v12.0.0</span>
</div>
<p></p><div class="api_stability api_stability_1"><a href="documentation.html#documentation_stability_index">Stability: 1</a> - Experimental</div><p></p>
<p>Specify the directory where the CPU profiles generated by <code>--cpu-prof</code> will
be placed.</p>
<p>The default value is controlled by the
<a href="#cli_diagnostic_dir_directory">--diagnostic-dir</a> command-line option.</p>
<h4><code>--cpu-prof-interval</code><span><a class="mark" href="#cli_cpu_prof_interval" id="cli_cpu_prof_interval">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v12.2.0</span>
</div>
<p></p><div class="api_stability api_stability_1"><a href="documentation.html#documentation_stability_index">Stability: 1</a> - Experimental</div><p></p>
<p>Specify the sampling interval in microseconds for the CPU profiles generated
by <code>--cpu-prof</code>. The default is 1000 microseconds.</p>
<h4><code>--cpu-prof-name</code><span><a class="mark" href="#cli_cpu_prof_name" id="cli_cpu_prof_name">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v12.0.0</span>
</div>
<p></p><div class="api_stability api_stability_1"><a href="documentation.html#documentation_stability_index">Stability: 1</a> - Experimental</div><p></p>
<p>Specify the file name of the CPU profile generated by <code>--cpu-prof</code>.</p>
<h4><code>--diagnostic-dir=directory</code><span><a class="mark" href="#cli_diagnostic_dir_directory" id="cli_diagnostic_dir_directory">#</a></span></h4>
<p>Set the directory to which all diagnostic output files are written.
Defaults to current working directory.</p>
<p>Affects the default output directory of:</p>
<ul>
<li><a href="#cli_cpu_prof_dir">--cpu-prof-dir</a></li>
<li><a href="#cli_heap_prof_dir">--heap-prof-dir</a></li>
<li><a href="#cli_redirect_warnings_file">--redirect-warnings</a></li>
</ul>
<h4><code>--disable-proto=mode</code><span><a class="mark" href="#cli_disable_proto_mode" id="cli_disable_proto_mode">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v13.12.0</span>
</div>
<p>Disable the <code>Object.prototype.__proto__</code> property. If <code>mode</code> is <code>delete</code>, the
property is removed entirely. If <code>mode</code> is <code>throw</code>, accesses to the
property throw an exception with the code <code>ERR_PROTO_ACCESS</code>.</p>
<h4><code>--disallow-code-generation-from-strings</code><span><a class="mark" href="#cli_disallow_code_generation_from_strings" id="cli_disallow_code_generation_from_strings">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v9.8.0</span>
</div>
<p>Make built-in language features like <code>eval</code> and <code>new Function</code> that generate
code from strings throw an exception instead. This does not affect the Node.js
<code>vm</code> module.</p>
<h4><code>--dns-result-order=order</code><span><a class="mark" href="#cli_dns_result_order_order" id="cli_dns_result_order_order">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v14.18.0</span>
</div>
<p>Set the default value of <code>verbatim</code> in <a href="dns.html#dns_dns_lookup_hostname_options_callback"><code>dns.lookup()</code></a> and
<a href="dns.html#dns_dnspromises_lookup_hostname_options"><code>dnsPromises.lookup()</code></a>. The value could be:</p>
<ul>
<li><code>ipv4first</code>: sets default <code>verbatim</code> <code>false</code>.</li>
<li><code>verbatim</code>: sets default <code>verbatim</code> <code>true</code>.</li>
</ul>
<p>The default is <code>ipv4first</code> and <a href="dns.html#dns_dns_setdefaultresultorder_order"><code>dns.setDefaultResultOrder()</code></a> have higher
priority than <code>--dns-result-order</code>.</p>
<h4><code>--enable-fips</code><span><a class="mark" href="#cli_enable_fips" id="cli_enable_fips">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v6.0.0</span>
</div>
<p>Enable FIPS-compliant crypto at startup. (Requires Node.js to be built
against FIPS-compatible OpenSSL.)</p>
<h4><code>--enable-source-maps</code><span><a class="mark" href="#cli_enable_source_maps" id="cli_enable_source_maps">#</a></span></h4>
<div class="api_metadata">
<details class="changelog"><summary>History</summary>
<table>
<tbody><tr><th>Version</th><th>Changes</th></tr>
<tr><td>v14.18.0</td>
<td><p>This API is no longer experimental.</p></td></tr>
<tr><td>v12.12.0</td>
<td><p><span>Added in: v12.12.0</span></p></td></tr>
</tbody></table>
</details>
</div>
<p>Enable <a href="https://sourcemaps.info/spec.html">Source Map v3</a> support for stack traces.</p>
<p>When using a transpiler, such as TypeScript, strack traces thrown by an
application reference the transpiled code, not the original source position.
<code>--enable-source-maps</code> enables caching of Source Maps and makes a best
effort to report stack traces relative to the original source file.</p>
<p>Overriding <code>Error.prepareStackTrace</code> prevents <code>--enable-source-maps</code> from
modifiying the stack trace.</p>
<h4><code>--experimental-abortcontroller</code><span><a class="mark" href="#cli_experimental_abortcontroller" id="cli_experimental_abortcontroller">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v14.17.0</span>
</div>
<p>Enable experimental <code>AbortController</code> and <code>AbortSignal</code> support.</p>
<h4><code>--experimental-import-meta-resolve</code><span><a class="mark" href="#cli_experimental_import_meta_resolve" id="cli_experimental_import_meta_resolve">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v13.9.0, v12.16.2</span>
</div>
<p>Enable experimental <code>import.meta.resolve()</code> support.</p>
<h4><code>--experimental-json-modules</code><span><a class="mark" href="#cli_experimental_json_modules" id="cli_experimental_json_modules">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v12.9.0</span>
</div>
<p>Enable experimental JSON support for the ES Module loader.</p>
<h4><code>--experimental-loader=module</code><span><a class="mark" href="#cli_experimental_loader_module" id="cli_experimental_loader_module">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v9.0.0</span>
</div>
<p>Specify the <code>module</code> of a custom experimental <a href="esm.html#esm_loaders">ECMAScript Module loader</a>.
<code>module</code> may be either a path to a file, or an ECMAScript Module name.</p>
<h4><code>--experimental-modules</code><span><a class="mark" href="#cli_experimental_modules" id="cli_experimental_modules">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v8.5.0</span>
</div>
<p>Enable latest experimental modules features (deprecated).</p>
<h4><code>--experimental-policy</code><span><a class="mark" href="#cli_experimental_policy" id="cli_experimental_policy">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v11.8.0</span>
</div>
<p>Use the specified file as a security policy.</p>
<h4><code>--experimental-repl-await</code><span><a class="mark" href="#cli_experimental_repl_await" id="cli_experimental_repl_await">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v10.0.0</span>
</div>
<p>Enable experimental top-level <code>await</code> keyword support in REPL.</p>
<h4><code>--experimental-specifier-resolution=mode</code><span><a class="mark" href="#cli_experimental_specifier_resolution_mode" id="cli_experimental_specifier_resolution_mode">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v13.4.0, v12.16.0</span>
</div>
<p>Sets the resolution algorithm for resolving ES module specifiers. Valid options
are <code>explicit</code> and <code>node</code>.</p>
<p>The default is <code>explicit</code>, which requires providing the full path to a
module. The <code>node</code> mode enables support for optional file extensions and
the ability to import a directory that has an index file.</p>
<p>See <a href="esm.html#esm_customizing_esm_specifier_resolution_algorithm">customizing ESM specifier resolution</a> for example usage.</p>
<h4><code>--experimental-vm-modules</code><span><a class="mark" href="#cli_experimental_vm_modules" id="cli_experimental_vm_modules">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v9.6.0</span>
</div>
<p>Enable experimental ES Module support in the <code>vm</code> module.</p>
<h4><code>--experimental-wasi-unstable-preview1</code><span><a class="mark" href="#cli_experimental_wasi_unstable_preview1" id="cli_experimental_wasi_unstable_preview1">#</a></span></h4>
<div class="api_metadata">
<details class="changelog"><summary>History</summary>
<table>
<tbody><tr><th>Version</th><th>Changes</th></tr>
<tr><td>v13.6.0</td>
<td><p>changed from <code>--experimental-wasi-unstable-preview0</code> to <code>--experimental-wasi-unstable-preview1</code>.</p></td></tr>
<tr><td>v13.3.0, v12.16.0</td>
<td><p><span>Added in: v13.3.0, v12.16.0</span></p></td></tr>
</tbody></table>
</details>
</div>
<p>Enable experimental WebAssembly System Interface (WASI) support.</p>
<h4><code>--experimental-wasm-modules</code><span><a class="mark" href="#cli_experimental_wasm_modules" id="cli_experimental_wasm_modules">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v12.3.0</span>
</div>
<p>Enable experimental WebAssembly module support.</p>
<h4><code>--force-context-aware</code><span><a class="mark" href="#cli_force_context_aware" id="cli_force_context_aware">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v12.12.0</span>
</div>
<p>Disable loading native addons that are not <a href="addons.html#addons_context_aware_addons">context-aware</a>.</p>
<h4><code>--force-fips</code><span><a class="mark" href="#cli_force_fips" id="cli_force_fips">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v6.0.0</span>
</div>
<p>Force FIPS-compliant crypto on startup. (Cannot be disabled from script code.)
(Same requirements as <code>--enable-fips</code>.)</p>
<h4><code>--frozen-intrinsics</code><span><a class="mark" href="#cli_frozen_intrinsics" id="cli_frozen_intrinsics">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v11.12.0</span>
</div>
<p></p><div class="api_stability api_stability_1"><a href="documentation.html#documentation_stability_index">Stability: 1</a> - Experimental</div><p></p>
<p>Enable experimental frozen intrinsics like <code>Array</code> and <code>Object</code>.</p>
<p>Support is currently only provided for the root context and no guarantees are
currently provided that <code>global.Array</code> is indeed the default intrinsic
reference. Code may break under this flag.</p>
<p><code>--require</code> runs prior to freezing intrinsics in order to allow polyfills to
be added.</p>
<h4><code>--heapsnapshot-near-heap-limit=max_count</code><span><a class="mark" href="#cli_heapsnapshot_near_heap_limit_max_count" id="cli_heapsnapshot_near_heap_limit_max_count">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v14.18.0</span>
</div>
<p></p><div class="api_stability api_stability_1"><a href="documentation.html#documentation_stability_index">Stability: 1</a> - Experimental</div><p></p>
<p>Writes a V8 heap snapshot to disk when the V8 heap usage is approaching the
heap limit. <code>count</code> should be a non-negative integer (in which case
Node.js will write no more than <code>max_count</code> snapshots to disk).</p>
<p>When generating snapshots, garbage collection may be triggered and bring
the heap usage down, therefore multiple snapshots may be written to disk
before the Node.js instance finally runs out of memory. These heap snapshots
can be compared to determine what objects are being allocated during the
time consecutive snapshots are taken. It's not guaranteed that Node.js will
write exactly <code>max_count</code> snapshots to disk, but it will try
its best to generate at least one and up to <code>max_count</code> snapshots before the
Node.js instance runs out of memory when <code>max_count</code> is greater than <code>0</code>.</p>
<p>Generating V8 snapshots takes time and memory (both memory managed by the
V8 heap and native memory outside the V8 heap). The bigger the heap is,
the more resources it needs. Node.js will adjust the V8 heap to accommondate
the additional V8 heap memory overhead, and try its best to avoid using up
all the memory avialable to the process. When the process uses
more memory than the system deems appropriate, the process may be terminated
abruptly by the system, depending on the system configuration.</p>
<pre><code class="language-console"><span class="hljs-meta">$ </span><span class="language-bash">node --max-old-space-size=100 --heapsnapshot-near-heap-limit=3 index.js</span>
Wrote snapshot to Heap.20200430.100036.49580.0.001.heapsnapshot
Wrote snapshot to Heap.20200430.100037.49580.0.002.heapsnapshot
Wrote snapshot to Heap.20200430.100038.49580.0.003.heapsnapshot

&#x3C;--- Last few GCs --->

[49580:0x110000000]     4826 ms: Mark-sweep 130.6 (147.8) -> 130.5 (147.8) MB, 27.4 / 0.0 ms  (average mu = 0.126, current mu = 0.034) allocation failure scavenge might not succeed
[49580:0x110000000]     4845 ms: Mark-sweep 130.6 (147.8) -> 130.6 (147.8) MB, 18.8 / 0.0 ms  (average mu = 0.088, current mu = 0.031) allocation failure scavenge might not succeed


&#x3C;--- JS stacktrace --->

FATAL ERROR: Ineffective mark-compacts near heap limit Allocation failed - JavaScript heap out of memory
....</code></pre>
<h4><code>--heapsnapshot-signal=signal</code><span><a class="mark" href="#cli_heapsnapshot_signal_signal" id="cli_heapsnapshot_signal_signal">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v12.0.0</span>
</div>
<p>Enables a signal handler that causes the Node.js process to write a heap dump
when the specified signal is received. <code>signal</code> must be a valid signal name.
Disabled by default.</p>
<pre><code class="language-console"><span class="hljs-meta">$ </span><span class="language-bash">node --heapsnapshot-signal=SIGUSR2 index.js &#x26;</span>
<span class="hljs-meta">$ </span><span class="language-bash">ps aux</span>
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
node         1  5.5  6.1 787252 247004 ?       Ssl  16:43   0:02 node --heapsnapshot-signal=SIGUSR2 index.js
<span class="hljs-meta">$ </span><span class="language-bash"><span class="hljs-built_in">kill</span> -USR2 1</span>
<span class="hljs-meta">$ </span><span class="language-bash">ls</span>
Heap.20190718.133405.15554.0.001.heapsnapshot</code></pre>
<h4><code>--heap-prof</code><span><a class="mark" href="#cli_heap_prof" id="cli_heap_prof">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v12.4.0</span>
</div>
<p></p><div class="api_stability api_stability_1"><a href="documentation.html#documentation_stability_index">Stability: 1</a> - Experimental</div><p></p>
<p>Starts the V8 heap profiler on start up, and writes the heap profile to disk
before exit.</p>
<p>If <code>--heap-prof-dir</code> is not specified, the generated profile is placed
in the current working directory.</p>
<p>If <code>--heap-prof-name</code> is not specified, the generated profile is
named <code>Heap.${yyyymmdd}.${hhmmss}.${pid}.${tid}.${seq}.heapprofile</code>.</p>
<pre><code class="language-console"><span class="hljs-meta">$ </span><span class="language-bash">node --heap-prof index.js</span>
<span class="hljs-meta">$ </span><span class="language-bash">ls *.heapprofile</span>
Heap.20190409.202950.15293.0.001.heapprofile</code></pre>
<h4><code>--heap-prof-dir</code><span><a class="mark" href="#cli_heap_prof_dir" id="cli_heap_prof_dir">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v12.4.0</span>
</div>
<p></p><div class="api_stability api_stability_1"><a href="documentation.html#documentation_stability_index">Stability: 1</a> - Experimental</div><p></p>
<p>Specify the directory where the heap profiles generated by <code>--heap-prof</code> will
be placed.</p>
<p>The default value is controlled by the
<a href="#cli_diagnostic_dir_directory">--diagnostic-dir</a> command-line option.</p>
<h4><code>--heap-prof-interval</code><span><a class="mark" href="#cli_heap_prof_interval" id="cli_heap_prof_interval">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v12.4.0</span>
</div>
<p></p><div class="api_stability api_stability_1"><a href="documentation.html#documentation_stability_index">Stability: 1</a> - Experimental</div><p></p>
<p>Specify the average sampling interval in bytes for the heap profiles generated
by <code>--heap-prof</code>. The default is 512 * 1024 bytes.</p>
<h4><code>--heap-prof-name</code><span><a class="mark" href="#cli_heap_prof_name" id="cli_heap_prof_name">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v12.4.0</span>
</div>
<p></p><div class="api_stability api_stability_1"><a href="documentation.html#documentation_stability_index">Stability: 1</a> - Experimental</div><p></p>
<p>Specify the file name of the heap profile generated by <code>--heap-prof</code>.</p>
<h4><code>--icu-data-dir=file</code><span><a class="mark" href="#cli_icu_data_dir_file" id="cli_icu_data_dir_file">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v0.11.15</span>
</div>
<p>Specify ICU data load path. (Overrides <code>NODE_ICU_DATA</code>.)</p>
<h4><code>--input-type=type</code><span><a class="mark" href="#cli_input_type_type" id="cli_input_type_type">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v12.0.0</span>
</div>
<p>This configures Node.js to interpret string input as CommonJS or as an ES
module. String input is input via <code>--eval</code>, <code>--print</code>, or <code>STDIN</code>.</p>
<p>Valid values are <code>"commonjs"</code> and <code>"module"</code>. The default is <code>"commonjs"</code>.</p>
<h4><code>--inspect-brk[=[host:]port]</code><span><a class="mark" href="#cli_inspect_brk_host_port" id="cli_inspect_brk_host_port">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v7.6.0</span>
</div>
<p>Activate inspector on <code>host:port</code> and break at start of user script.
Default <code>host:port</code> is <code>127.0.0.1:9229</code>.</p>
<h4><code>--inspect-port=[host:]port</code><span><a class="mark" href="#cli_inspect_port_host_port" id="cli_inspect_port_host_port">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v7.6.0</span>
</div>
<p>Set the <code>host:port</code> to be used when the inspector is activated.
Useful when activating the inspector by sending the <code>SIGUSR1</code> signal.</p>
<p>Default host is <code>127.0.0.1</code>.</p>
<p>See the <a href="#inspector_security">security warning</a> below regarding the <code>host</code>
parameter usage.</p>
<h4><code>--inspect[=[host:]port]</code><span><a class="mark" href="#cli_inspect_host_port" id="cli_inspect_host_port">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v6.3.0</span>
</div>
<p>Activate inspector on <code>host:port</code>. Default is <code>127.0.0.1:9229</code>.</p>
<p>V8 inspector integration allows tools such as Chrome DevTools and IDEs to debug
and profile Node.js instances. The tools attach to Node.js instances via a
tcp port and communicate using the <a href="https://chromedevtools.github.io/devtools-protocol/">Chrome DevTools Protocol</a>.</p>
<p><a id="inspector_security"></a></p>
<h5>Warning: binding inspector to a public IP:port combination is insecure<span><a class="mark" href="#cli_warning_binding_inspector_to_a_public_ip_port_combination_is_insecure" id="cli_warning_binding_inspector_to_a_public_ip_port_combination_is_insecure">#</a></span></h5>
<p>Binding the inspector to a public IP (including <code>0.0.0.0</code>) with an open port is
insecure, as it allows external hosts to connect to the inspector and perform
a <a href="https://www.owasp.org/index.php/Code_Injection">remote code execution</a> attack.</p>
<p>If specifying a host, make sure that either:</p>
<ul>
<li>The host is not accessible from public networks.</li>
<li>A firewall disallows unwanted connections on the port.</li>
</ul>
<p><strong>More specifically, <code>--inspect=0.0.0.0</code> is insecure if the port (<code>9229</code> by
default) is not firewall-protected.</strong></p>
<p>See the <a href="https://nodejs.org/en/docs/guides/debugging-getting-started/#security-implications">debugging security implications</a> section for more information.</p>
<h4><code>--inspect-publish-uid=stderr,http</code><span><a class="mark" href="#cli_inspect_publish_uid_stderr_http" id="cli_inspect_publish_uid_stderr_http">#</a></span></h4>
<p>Specify ways of the inspector web socket url exposure.</p>
<p>By default inspector websocket url is available in stderr and under <code>/json/list</code>
endpoint on <code>http://host:port/json/list</code>.</p>
<h4><code>--insecure-http-parser</code><span><a class="mark" href="#cli_insecure_http_parser" id="cli_insecure_http_parser">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v13.4.0, v12.15.0, v10.19.0</span>
</div>
<p>Use an insecure HTTP parser that accepts invalid HTTP headers. This may allow
interoperability with non-conformant HTTP implementations. It may also allow
request smuggling and other HTTP attacks that rely on invalid headers being
accepted. Avoid using this option.</p>
<h4><code>--jitless</code><span><a class="mark" href="#cli_jitless" id="cli_jitless">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v12.0.0</span>
</div>
<p>Disable <a href="https://v8.dev/blog/jitless">runtime allocation of executable memory</a>. This may be
required on some platforms for security reasons. It can also reduce attack
surface on other platforms, but the performance impact may be severe.</p>
<p>This flag is inherited from V8 and is subject to change upstream. It may
disappear in a non-semver-major release.</p>
<h4><code>--max-http-header-size=size</code><span><a class="mark" href="#cli_max_http_header_size_size" id="cli_max_http_header_size_size">#</a></span></h4>
<div class="api_metadata">
<details class="changelog"><summary>History</summary>
<table>
<tbody><tr><th>Version</th><th>Changes</th></tr>
<tr><td>v14.0.0</td>
<td><p>Change maximum default size of HTTP headers from 8KB to 16KB.</p></td></tr>
<tr><td>v11.6.0, v10.15.0</td>
<td><p><span>Added in: v11.6.0, v10.15.0</span></p></td></tr>
</tbody></table>
</details>
</div>
<p>Specify the maximum size, in bytes, of HTTP headers. Defaults to 16KB.</p>
<h4><code>--napi-modules</code><span><a class="mark" href="#cli_napi_modules" id="cli_napi_modules">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v7.10.0</span>
</div>
<p>This option is a no-op. It is kept for compatibility.</p>
<h4><code>--no-addons</code><span><a class="mark" href="#cli_no_addons" id="cli_no_addons">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v14.19.0</span>
</div>
<p>Disable the <code>node-addons</code> exports condition as well as disable loading
native addons. When <code>--no-addons</code> is specified, calling <code>process.dlopen</code> or
requiring a native C++ addon will fail and throw an exception.</p>
<h4><code>--no-deprecation</code><span><a class="mark" href="#cli_no_deprecation" id="cli_no_deprecation">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v0.8.0</span>
</div>
<p>Silence deprecation warnings.</p>
<h4><code>--no-force-async-hooks-checks</code><span><a class="mark" href="#cli_no_force_async_hooks_checks" id="cli_no_force_async_hooks_checks">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v9.0.0</span>
</div>
<p>Disables runtime checks for <code>async_hooks</code>. These will still be enabled
dynamically when <code>async_hooks</code> is enabled.</p>
<h4><code>--no-warnings</code><span><a class="mark" href="#cli_no_warnings" id="cli_no_warnings">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v6.0.0</span>
</div>
<p>Silence all process warnings (including deprecations).</p>
<h4><code>--node-memory-debug</code><span><a class="mark" href="#cli_node_memory_debug" id="cli_node_memory_debug">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v14.18.0</span>
</div>
<p>Enable extra debug checks for memory leaks in Node.js internals. This is
usually only useful for developers debugging Node.js itself.</p>
<h4><code>--openssl-config=file</code><span><a class="mark" href="#cli_openssl_config_file" id="cli_openssl_config_file">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v6.9.0</span>
</div>
<p>Load an OpenSSL configuration file on startup. Among other uses, this can be
used to enable FIPS-compliant crypto if Node.js is built
against FIPS-enabled OpenSSL.</p>
<h4><code>--pending-deprecation</code><span><a class="mark" href="#cli_pending_deprecation" id="cli_pending_deprecation">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v8.0.0</span>
</div>
<p>Emit pending deprecation warnings.</p>
<p>Pending deprecations are generally identical to a runtime deprecation with the
notable exception that they are turned <em>off</em> by default and will not be emitted
unless either the <code>--pending-deprecation</code> command-line flag, or the
<code>NODE_PENDING_DEPRECATION=1</code> environment variable, is set. Pending deprecations
are used to provide a kind of selective "early warning" mechanism that
developers may leverage to detect deprecated API usage.</p>
<h4><code>--policy-integrity=sri</code><span><a class="mark" href="#cli_policy_integrity_sri" id="cli_policy_integrity_sri">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v12.7.0</span>
</div>
<p></p><div class="api_stability api_stability_1"><a href="documentation.html#documentation_stability_index">Stability: 1</a> - Experimental</div><p></p>
<p>Instructs Node.js to error prior to running any code if the policy does not have
the specified integrity. It expects a <a href="https://developer.mozilla.org/en-US/docs/Web/Security/Subresource_Integrity">Subresource Integrity</a> string as a
parameter.</p>
<h4><code>--preserve-symlinks</code><span><a class="mark" href="#cli_preserve_symlinks" id="cli_preserve_symlinks">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v6.3.0</span>
</div>
<p>Instructs the module loader to preserve symbolic links when resolving and
caching modules.</p>
<p>By default, when Node.js loads a module from a path that is symbolically linked
to a different on-disk location, Node.js will dereference the link and use the
actual on-disk "real path" of the module as both an identifier and as a root
path to locate other dependency modules. In most cases, this default behavior
is acceptable. However, when using symbolically linked peer dependencies, as
illustrated in the example below, the default behavior causes an exception to
be thrown if <code>moduleA</code> attempts to require <code>moduleB</code> as a peer dependency:</p>
<pre><code class="language-text">{appDir}
 ├── app
 │   ├── index.js
 │   └── node_modules
 │       ├── moduleA -> {appDir}/moduleA
 │       └── moduleB
 │           ├── index.js
 │           └── package.json
 └── moduleA
     ├── index.js
     └── package.json</code></pre>
<p>The <code>--preserve-symlinks</code> command-line flag instructs Node.js to use the
symlink path for modules as opposed to the real path, allowing symbolically
linked peer dependencies to be found.</p>
<p>Note, however, that using <code>--preserve-symlinks</code> can have other side effects.
Specifically, symbolically linked <em>native</em> modules can fail to load if those
are linked from more than one location in the dependency tree (Node.js would
see those as two separate modules and would attempt to load the module multiple
times, causing an exception to be thrown).</p>
<p>The <code>--preserve-symlinks</code> flag does not apply to the main module, which allows
<code>node --preserve-symlinks node_module/.bin/&#x3C;foo></code> to work. To apply the same
behavior for the main module, also use <code>--preserve-symlinks-main</code>.</p>
<h4><code>--preserve-symlinks-main</code><span><a class="mark" href="#cli_preserve_symlinks_main" id="cli_preserve_symlinks_main">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v10.2.0</span>
</div>
<p>Instructs the module loader to preserve symbolic links when resolving and
caching the main module (<code>require.main</code>).</p>
<p>This flag exists so that the main module can be opted-in to the same behavior
that <code>--preserve-symlinks</code> gives to all other imports; they are separate flags,
however, for backward compatibility with older Node.js versions.</p>
<p><code>--preserve-symlinks-main</code> does not imply <code>--preserve-symlinks</code>; use
<code>--preserve-symlinks-main</code> in addition to
<code>--preserve-symlinks</code> when it is not desirable to follow symlinks before
resolving relative paths.</p>
<p>See <code>--preserve-symlinks</code> for more information.</p>
<h4><code>--prof</code><span><a class="mark" href="#cli_prof" id="cli_prof">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v2.0.0</span>
</div>
<p>Generate V8 profiler output.</p>
<h4><code>--prof-process</code><span><a class="mark" href="#cli_prof_process" id="cli_prof_process">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v5.2.0</span>
</div>
<p>Process V8 profiler output generated using the V8 option <code>--prof</code>.</p>
<h4><code>--redirect-warnings=file</code><span><a class="mark" href="#cli_redirect_warnings_file" id="cli_redirect_warnings_file">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v8.0.0</span>
</div>
<p>Write process warnings to the given file instead of printing to stderr. The
file will be created if it does not exist, and will be appended to if it does.
If an error occurs while attempting to write the warning to the file, the
warning will be written to stderr instead.</p>
<p>The <code>file</code> name may be an absolute path. If it is not, the default directory it
will be written to is controlled by the
<a href="#cli_diagnostic_dir_directory">--diagnostic-dir</a> command-line option.</p>
<h4><code>--report-compact</code><span><a class="mark" href="#cli_report_compact" id="cli_report_compact">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v13.12.0</span>
</div>
<p>Write reports in a compact format, single-line JSON, more easily consumable
by log processing systems than the default multi-line format designed for
human consumption.</p>
<h4><code>--report-dir=directory</code>, <code>report-directory=directory</code><span><a class="mark" href="#cli_report_dir_directory_report_directory_directory" id="cli_report_dir_directory_report_directory_directory">#</a></span></h4>
<div class="api_metadata">
<details class="changelog"><summary>History</summary>
<table>
<tbody><tr><th>Version</th><th>Changes</th></tr>
<tr><td>v13.12.0</td>
<td><p>This option is no longer experimental.</p></td></tr>
<tr><td>v12.0.0</td>
<td><p>Changed from <code>--diagnostic-report-directory</code> to <code>--report-directory</code>.</p></td></tr>
<tr><td>v11.8.0</td>
<td><p><span>Added in: v11.8.0</span></p></td></tr>
</tbody></table>
</details>
</div>
<p>Location at which the report will be generated.</p>
<h4><code>--report-filename=filename</code><span><a class="mark" href="#cli_report_filename_filename" id="cli_report_filename_filename">#</a></span></h4>
<div class="api_metadata">
<details class="changelog"><summary>History</summary>
<table>
<tbody><tr><th>Version</th><th>Changes</th></tr>
<tr><td>v13.12.0</td>
<td><p>This option is no longer experimental.</p></td></tr>
<tr><td>v12.0.0</td>
<td><p>changed from <code>--diagnostic-report-filename</code> to <code>--report-filename</code>.</p></td></tr>
<tr><td>v11.8.0</td>
<td><p><span>Added in: v11.8.0</span></p></td></tr>
</tbody></table>
</details>
</div>
<p>Name of the file to which the report will be written.</p>
<h4><code>--report-on-fatalerror</code><span><a class="mark" href="#cli_report_on_fatalerror" id="cli_report_on_fatalerror">#</a></span></h4>
<div class="api_metadata">
<details class="changelog"><summary>History</summary>
<table>
<tbody><tr><th>Version</th><th>Changes</th></tr>
<tr><td>v14.0.0</td>
<td><p>This option is no longer experimental.</p></td></tr>
<tr><td>v12.0.0</td>
<td><p>changed from <code>--diagnostic-report-on-fatalerror</code> to <code>--report-on-fatalerror</code>.</p></td></tr>
<tr><td>v11.8.0</td>
<td><p><span>Added in: v11.8.0</span></p></td></tr>
</tbody></table>
</details>
</div>
<p>Enables the report to be triggered on fatal errors (internal errors within
the Node.js runtime such as out of memory) that lead to termination of the
application. Useful to inspect various diagnostic data elements such as heap,
stack, event loop state, resource consumption etc. to reason about the fatal
error.</p>
<h4><code>--report-on-signal</code><span><a class="mark" href="#cli_report_on_signal" id="cli_report_on_signal">#</a></span></h4>
<div class="api_metadata">
<details class="changelog"><summary>History</summary>
<table>
<tbody><tr><th>Version</th><th>Changes</th></tr>
<tr><td>v13.12.0</td>
<td><p>This option is no longer experimental.</p></td></tr>
<tr><td>v12.0.0</td>
<td><p>changed from <code>--diagnostic-report-on-signal</code> to <code>--report-on-signal</code>.</p></td></tr>
<tr><td>v11.8.0</td>
<td><p><span>Added in: v11.8.0</span></p></td></tr>
</tbody></table>
</details>
</div>
<p>Enables report to be generated upon receiving the specified (or predefined)
signal to the running Node.js process. The signal to trigger the report is
specified through <code>--report-signal</code>.</p>
<h4><code>--report-signal=signal</code><span><a class="mark" href="#cli_report_signal_signal" id="cli_report_signal_signal">#</a></span></h4>
<div class="api_metadata">
<details class="changelog"><summary>History</summary>
<table>
<tbody><tr><th>Version</th><th>Changes</th></tr>
<tr><td>v13.12.0</td>
<td><p>This option is no longer experimental.</p></td></tr>
<tr><td>v12.0.0</td>
<td><p>changed from <code>--diagnostic-report-signal</code> to <code>--report-signal</code>.</p></td></tr>
<tr><td>v11.8.0</td>
<td><p><span>Added in: v11.8.0</span></p></td></tr>
</tbody></table>
</details>
</div>
<p>Sets or resets the signal for report generation (not supported on Windows).
Default signal is <code>SIGUSR2</code>.</p>
<h4><code>--report-uncaught-exception</code><span><a class="mark" href="#cli_report_uncaught_exception" id="cli_report_uncaught_exception">#</a></span></h4>
<div class="api_metadata">
<details class="changelog"><summary>History</summary>
<table>
<tbody><tr><th>Version</th><th>Changes</th></tr>
<tr><td>v13.12.0</td>
<td><p>This option is no longer experimental.</p></td></tr>
<tr><td>v12.0.0</td>
<td><p>changed from <code>--diagnostic-report-uncaught-exception</code> to <code>--report-uncaught-exception</code>.</p></td></tr>
<tr><td>v11.8.0</td>
<td><p><span>Added in: v11.8.0</span></p></td></tr>
</tbody></table>
</details>
</div>
<p>Enables report to be generated on uncaught exceptions. Useful when inspecting
the JavaScript stack in conjunction with native stack and other runtime
environment data.</p>
<h4><code>--throw-deprecation</code><span><a class="mark" href="#cli_throw_deprecation" id="cli_throw_deprecation">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v0.11.14</span>
</div>
<p>Throw errors for deprecations.</p>
<h4><code>--title=title</code><span><a class="mark" href="#cli_title_title" id="cli_title_title">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v10.7.0</span>
</div>
<p>Set <code>process.title</code> on startup.</p>
<h4><code>--tls-cipher-list=list</code><span><a class="mark" href="#cli_tls_cipher_list_list" id="cli_tls_cipher_list_list">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v4.0.0</span>
</div>
<p>Specify an alternative default TLS cipher list. Requires Node.js to be built
with crypto support (default).</p>
<h4><code>--tls-keylog=file</code><span><a class="mark" href="#cli_tls_keylog_file" id="cli_tls_keylog_file">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v13.2.0, v12.16.0</span>
</div>
<p>Log TLS key material to a file. The key material is in NSS <code>SSLKEYLOGFILE</code>
format and can be used by software (such as Wireshark) to decrypt the TLS
traffic.</p>
<h4><code>--tls-max-v1.2</code><span><a class="mark" href="#cli_tls_max_v1_2" id="cli_tls_max_v1_2">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v12.0.0, v10.20.0</span>
</div>
<p>Set <a href="tls.html#tls_tls_default_max_version"><code>tls.DEFAULT_MAX_VERSION</code></a> to 'TLSv1.2'. Use to disable support for
TLSv1.3.</p>
<h4><code>--tls-max-v1.3</code><span><a class="mark" href="#cli_tls_max_v1_3" id="cli_tls_max_v1_3">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v12.0.0</span>
</div>
<p>Set default <a href="tls.html#tls_tls_default_max_version"><code>tls.DEFAULT_MAX_VERSION</code></a> to 'TLSv1.3'. Use to enable support
for TLSv1.3.</p>
<h4><code>--tls-min-v1.0</code><span><a class="mark" href="#cli_tls_min_v1_0" id="cli_tls_min_v1_0">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v12.0.0, v10.20.0</span>
</div>
<p>Set default <a href="tls.html#tls_tls_default_min_version"><code>tls.DEFAULT_MIN_VERSION</code></a> to 'TLSv1'. Use for compatibility with
old TLS clients or servers.</p>
<h4><code>--tls-min-v1.1</code><span><a class="mark" href="#cli_tls_min_v1_1" id="cli_tls_min_v1_1">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v12.0.0, v10.20.0</span>
</div>
<p>Set default <a href="tls.html#tls_tls_default_min_version"><code>tls.DEFAULT_MIN_VERSION</code></a> to 'TLSv1.1'. Use for compatibility
with old TLS clients or servers.</p>
<h4><code>--tls-min-v1.2</code><span><a class="mark" href="#cli_tls_min_v1_2" id="cli_tls_min_v1_2">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v12.2.0, v10.20.0</span>
</div>
<p>Set default <a href="tls.html#tls_tls_default_min_version"><code>tls.DEFAULT_MIN_VERSION</code></a> to 'TLSv1.2'. This is the default for
12.x and later, but the option is supported for compatibility with older Node.js
versions.</p>
<h4><code>--tls-min-v1.3</code><span><a class="mark" href="#cli_tls_min_v1_3" id="cli_tls_min_v1_3">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v12.0.0</span>
</div>
<p>Set default <a href="tls.html#tls_tls_default_min_version"><code>tls.DEFAULT_MIN_VERSION</code></a> to 'TLSv1.3'. Use to disable support
for TLSv1.2, which is not as secure as TLSv1.3.</p>
<h4><code>--trace-atomics-wait</code><span><a class="mark" href="#cli_trace_atomics_wait" id="cli_trace_atomics_wait">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v14.3.0</span>
</div>
<p>Print short summaries of calls to <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Atomics/wait"><code>Atomics.wait()</code></a> to stderr.
The output could look like this:</p>
<pre><code class="language-text">(node:15701) [Thread 0] Atomics.wait(&#x26;lt;address> + 0, 1, inf) started
(node:15701) [Thread 0] Atomics.wait(&#x26;lt;address> + 0, 1, inf) did not wait because the values mismatched
(node:15701) [Thread 0] Atomics.wait(&#x26;lt;address> + 0, 0, 10) started
(node:15701) [Thread 0] Atomics.wait(&#x26;lt;address> + 0, 0, 10) timed out
(node:15701) [Thread 0] Atomics.wait(&#x26;lt;address> + 4, 0, inf) started
(node:15701) [Thread 1] Atomics.wait(&#x26;lt;address> + 4, -1, inf) started
(node:15701) [Thread 0] Atomics.wait(&#x26;lt;address> + 4, 0, inf) was woken up by another thread
(node:15701) [Thread 1] Atomics.wait(&#x26;lt;address> + 4, -1, inf) was woken up by another thread</code></pre>
<p>The fields here correspond to:</p>
<ul>
<li>The thread id as given by <a href="worker_threads.html#worker_threads_worker_threadid"><code>worker_threads.threadId</code></a></li>
<li>The base address of the <code>SharedArrayBuffer</code> in question, as well as the
byte offset corresponding to the index passed to <code>Atomics.wait()</code></li>
<li>The expected value that was passed to <code>Atomics.wait()</code></li>
<li>The timeout passed to <code>Atomics.wait</code></li>
</ul>
<h4><code>--trace-deprecation</code><span><a class="mark" href="#cli_trace_deprecation" id="cli_trace_deprecation">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v0.8.0</span>
</div>
<p>Print stack traces for deprecations.</p>
<h4><code>--trace-event-categories</code><span><a class="mark" href="#cli_trace_event_categories" id="cli_trace_event_categories">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v7.7.0</span>
</div>
<p>A comma separated list of categories that should be traced when trace event
tracing is enabled using <code>--trace-events-enabled</code>.</p>
<h4><code>--trace-event-file-pattern</code><span><a class="mark" href="#cli_trace_event_file_pattern" id="cli_trace_event_file_pattern">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v9.8.0</span>
</div>
<p>Template string specifying the filepath for the trace event data, it
supports <code>${rotation}</code> and <code>${pid}</code>.</p>
<h4><code>--trace-events-enabled</code><span><a class="mark" href="#cli_trace_events_enabled" id="cli_trace_events_enabled">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v7.7.0</span>
</div>
<p>Enables the collection of trace event tracing information.</p>
<h4><code>--trace-exit</code><span><a class="mark" href="#cli_trace_exit" id="cli_trace_exit">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v13.5.0, v12.16.0</span>
</div>
<p>Prints a stack trace whenever an environment is exited proactively,
i.e. invoking <code>process.exit()</code>.</p>
<h4><code>--trace-sigint</code><span><a class="mark" href="#cli_trace_sigint" id="cli_trace_sigint">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v13.9.0</span>
</div>
<p>Prints a stack trace on SIGINT.</p>
<h4><code>--trace-sync-io</code><span><a class="mark" href="#cli_trace_sync_io" id="cli_trace_sync_io">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v2.1.0</span>
</div>
<p>Prints a stack trace whenever synchronous I/O is detected after the first turn
of the event loop.</p>
<h4><code>--trace-tls</code><span><a class="mark" href="#cli_trace_tls" id="cli_trace_tls">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v12.2.0</span>
</div>
<p>Prints TLS packet trace information to <code>stderr</code>. This can be used to debug TLS
connection problems.</p>
<h4><code>--trace-uncaught</code><span><a class="mark" href="#cli_trace_uncaught" id="cli_trace_uncaught">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v13.1.0</span>
</div>
<p>Print stack traces for uncaught exceptions; usually, the stack trace associated
with the creation of an <code>Error</code> is printed, whereas this makes Node.js also
print the stack trace associated with throwing the value (which does not need
to be an <code>Error</code> instance).</p>
<p>Enabling this option may affect garbage collection behavior negatively.</p>
<h4><code>--trace-warnings</code><span><a class="mark" href="#cli_trace_warnings" id="cli_trace_warnings">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v6.0.0</span>
</div>
<p>Print stack traces for process warnings (including deprecations).</p>
<h4><code>--track-heap-objects</code><span><a class="mark" href="#cli_track_heap_objects" id="cli_track_heap_objects">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v2.4.0</span>
</div>
<p>Track heap object allocations for heap snapshots.</p>
<h4><code>--unhandled-rejections=mode</code><span><a class="mark" href="#cli_unhandled_rejections_mode" id="cli_unhandled_rejections_mode">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v12.0.0, v10.17.0</span>
</div>
<p>By default all unhandled rejections trigger a warning plus a deprecation warning
for the very first unhandled rejection in case no <a href="process.html#process_event_unhandledrejection"><code>unhandledRejection</code></a> hook
is used.</p>
<p>Using this flag allows to change what should happen when an unhandled rejection
occurs. One of the following modes can be chosen:</p>
<ul>
<li><code>throw</code>: Emit <a href="process.html#process_event_unhandledrejection"><code>unhandledRejection</code></a>. If this hook is not set, raise the
unhandled rejection as an uncaught exception.</li>
<li><code>strict</code>: Raise the unhandled rejection as an uncaught exception.</li>
<li><code>warn</code>: Always trigger a warning, no matter if the <a href="process.html#process_event_unhandledrejection"><code>unhandledRejection</code></a>
hook is set or not but do not print the deprecation warning.</li>
<li><code>warn-with-error-code</code>: Emit <a href="process.html#process_event_unhandledrejection"><code>unhandledRejection</code></a>. If this hook is not
set, trigger a warning, and set the process exit code to 1.</li>
<li><code>none</code>: Silence all warnings.</li>
</ul>
<h4><code>--use-bundled-ca</code>, <code>--use-openssl-ca</code><span><a class="mark" href="#cli_use_bundled_ca_use_openssl_ca" id="cli_use_bundled_ca_use_openssl_ca">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v6.11.0</span>
</div>
<p>Use bundled Mozilla CA store as supplied by current Node.js version
or use OpenSSL's default CA store. The default store is selectable
at build-time.</p>
<p>The bundled CA store, as supplied by Node.js, is a snapshot of Mozilla CA store
that is fixed at release time. It is identical on all supported platforms.</p>
<p>Using OpenSSL store allows for external modifications of the store. For most
Linux and BSD distributions, this store is maintained by the distribution
maintainers and system administrators. OpenSSL CA store location is dependent on
configuration of the OpenSSL library but this can be altered at runtime using
environment variables.</p>
<p>See <code>SSL_CERT_DIR</code> and <code>SSL_CERT_FILE</code>.</p>
<h4><code>--use-largepages=mode</code><span><a class="mark" href="#cli_use_largepages_mode" id="cli_use_largepages_mode">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v13.6.0</span>
</div>
<p>Re-map the Node.js static code to large memory pages at startup. If supported on
the target system, this will cause the Node.js static code to be moved onto 2
MiB pages instead of 4 KiB pages.</p>
<p>The following values are valid for <code>mode</code>:</p>
<ul>
<li><code>off</code>: No mapping will be attempted. This is the default.</li>
<li><code>on</code>: If supported by the OS, mapping will be attempted. Failure to map will
be ignored and a message will be printed to standard error.</li>
<li><code>silent</code>: If supported by the OS, mapping will be attempted. Failure to map
will be ignored and will not be reported.</li>
</ul>
<h4><code>--v8-options</code><span><a class="mark" href="#cli_v8_options" id="cli_v8_options">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v0.1.3</span>
</div>
<p>Print V8 command-line options.</p>
<h4><code>--v8-pool-size=num</code><span><a class="mark" href="#cli_v8_pool_size_num" id="cli_v8_pool_size_num">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v5.10.0</span>
</div>
<p>Set V8's thread pool size which will be used to allocate background jobs.</p>
<p>If set to <code>0</code> then V8 will choose an appropriate size of the thread pool based
on the number of online processors.</p>
<p>If the value provided is larger than V8's maximum, then the largest value
will be chosen.</p>
<h4><code>--zero-fill-buffers</code><span><a class="mark" href="#cli_zero_fill_buffers" id="cli_zero_fill_buffers">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v6.0.0</span>
</div>
<p>Automatically zero-fills all newly allocated <a href="buffer.html#buffer_class_buffer"><code>Buffer</code></a> and <a href="buffer.html#buffer_class_slowbuffer"><code>SlowBuffer</code></a>
instances.</p>
<h4><code>-c</code>, <code>--check</code><span><a class="mark" href="#cli_c_check" id="cli_c_check">#</a></span></h4>
<div class="api_metadata">
<details class="changelog"><summary>History</summary>
<table>
<tbody><tr><th>Version</th><th>Changes</th></tr>
<tr><td>v10.0.0</td>
<td><p>The <code>--require</code> option is now supported when checking a file.</p></td></tr>
<tr><td>v5.0.0, v4.2.0</td>
<td><p><span>Added in: v5.0.0, v4.2.0</span></p></td></tr>
</tbody></table>
</details>
</div>
<p>Syntax check the script without executing.</p>
<h4><code>-e</code>, <code>--eval "script"</code><span><a class="mark" href="#cli_e_eval_script" id="cli_e_eval_script">#</a></span></h4>
<div class="api_metadata">
<details class="changelog"><summary>History</summary>
<table>
<tbody><tr><th>Version</th><th>Changes</th></tr>
<tr><td>v5.11.0</td>
<td><p>Built-in libraries are now available as predefined variables.</p></td></tr>
<tr><td>v0.5.2</td>
<td><p><span>Added in: v0.5.2</span></p></td></tr>
</tbody></table>
</details>
</div>
<p>Evaluate the following argument as JavaScript. The modules which are
predefined in the REPL can also be used in <code>script</code>.</p>
<p>On Windows, using <code>cmd.exe</code> a single quote will not work correctly because it
only recognizes double <code>"</code> for quoting. In Powershell or Git bash, both <code>'</code>
and <code>"</code> are usable.</p>
<h4><code>-h</code>, <code>--help</code><span><a class="mark" href="#cli_h_help" id="cli_h_help">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v0.1.3</span>
</div>
<p>Print node command-line options.
The output of this option is less detailed than this document.</p>
<h4><code>-i</code>, <code>--interactive</code><span><a class="mark" href="#cli_i_interactive" id="cli_i_interactive">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v0.7.7</span>
</div>
<p>Opens the REPL even if stdin does not appear to be a terminal.</p>
<h4><code>-p</code>, <code>--print "script"</code><span><a class="mark" href="#cli_p_print_script" id="cli_p_print_script">#</a></span></h4>
<div class="api_metadata">
<details class="changelog"><summary>History</summary>
<table>
<tbody><tr><th>Version</th><th>Changes</th></tr>
<tr><td>v5.11.0</td>
<td><p>Built-in libraries are now available as predefined variables.</p></td></tr>
<tr><td>v0.6.4</td>
<td><p><span>Added in: v0.6.4</span></p></td></tr>
</tbody></table>
</details>
</div>
<p>Identical to <code>-e</code> but prints the result.</p>
<h4><code>-r</code>, <code>--require module</code><span><a class="mark" href="#cli_r_require_module" id="cli_r_require_module">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v1.6.0</span>
</div>
<p>Preload the specified module at startup.</p>
<p>Follows <code>require()</code>'s module resolution
rules. <code>module</code> may be either a path to a file, or a node module name.</p>
<p>Only CommonJS modules are supported. Attempting to preload a
ES6 Module using <code>--require</code> will fail with an error.</p>
<h4><code>-v</code>, <code>--version</code><span><a class="mark" href="#cli_v_version" id="cli_v_version">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v0.1.3</span>
</div>
<p>Print node's version.</p>
</section><section><h3>Environment variables<span><a class="mark" href="#cli_environment_variables" id="cli_environment_variables">#</a></span></h3>
<h4><code>FORCE_COLOR=[1, 2, 3]</code><span><a class="mark" href="#cli_force_color_1_2_3" id="cli_force_color_1_2_3">#</a></span></h4>
<p>The <code>FORCE_COLOR</code> environment variable is used to
enable ANSI colorized output. The value may be:</p>
<ul>
<li><code>1</code>, <code>true</code>, or the empty string <code>''</code> indicate 16-color support,</li>
<li><code>2</code> to indicate 256-color support, or</li>
<li><code>3</code> to indicate 16 million-color support.</li>
</ul>
<p>When <code>FORCE_COLOR</code> is used and set to a supported value, both the <code>NO_COLOR</code>,
and <code>NODE_DISABLE_COLORS</code> environment variables are ignored.</p>
<p>Any other value will result in colorized output being disabled.</p>
<h4><code>NODE_DEBUG=module[,…]</code><span><a class="mark" href="#cli_node_debug_module" id="cli_node_debug_module">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v0.1.32</span>
</div>
<p><code>','</code>-separated list of core modules that should print debug information.</p>
<h4><code>NODE_DEBUG_NATIVE=module[,…]</code><span><a class="mark" href="#cli_node_debug_native_module" id="cli_node_debug_native_module">#</a></span></h4>
<p><code>','</code>-separated list of core C++ modules that should print debug information.</p>
<h4><code>NODE_DISABLE_COLORS=1</code><span><a class="mark" href="#cli_node_disable_colors_1" id="cli_node_disable_colors_1">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v0.3.0</span>
</div>
<p>When set, colors will not be used in the REPL.</p>
<h4><code>NODE_EXTRA_CA_CERTS=file</code><span><a class="mark" href="#cli_node_extra_ca_certs_file" id="cli_node_extra_ca_certs_file">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v7.3.0</span>
</div>
<p>When set, the well known "root" CAs (like VeriSign) will be extended with the
extra certificates in <code>file</code>. The file should consist of one or more trusted
certificates in PEM format. A message will be emitted (once) with
<a href="process.html#process_process_emitwarning_warning_type_code_ctor"><code>process.emitWarning()</code></a> if the file is missing or
malformed, but any errors are otherwise ignored.</p>
<p>Neither the well known nor extra certificates are used when the <code>ca</code>
options property is explicitly specified for a TLS or HTTPS client or server.</p>
<p>This environment variable is ignored when <code>node</code> runs as setuid root or
has Linux file capabilities set.</p>
<p>The <code>NODE_EXTRA_CA_CERTS</code> environment variable is only read when the Node.js
process is first launched. Changing the value at runtime using
<code>process.env.NODE_EXTRA_CA_CERTS</code> has no effect on the current process.</p>
<h4><code>NODE_ICU_DATA=file</code><span><a class="mark" href="#cli_node_icu_data_file" id="cli_node_icu_data_file">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v0.11.15</span>
</div>
<p>Data path for ICU (<code>Intl</code> object) data. Will extend linked-in data when compiled
with small-icu support.</p>
<h4><code>NODE_NO_WARNINGS=1</code><span><a class="mark" href="#cli_node_no_warnings_1" id="cli_node_no_warnings_1">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v6.11.0</span>
</div>
<p>When set to <code>1</code>, process warnings are silenced.</p>
<h4><code>NODE_OPTIONS=options...</code><span><a class="mark" href="#cli_node_options_options" id="cli_node_options_options">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v8.0.0</span>
</div>
<p>A space-separated list of command-line options. <code>options...</code> are interpreted
before command-line options, so command-line options will override or
compound after anything in <code>options...</code>. Node.js will exit with an error if
an option that is not allowed in the environment is used, such as <code>-p</code> or a
script file.</p>
<p>If an option value contains a space, it can be escaped using double quotes:</p>
<pre><code class="language-bash">NODE_OPTIONS=<span class="hljs-string">'--require "./my path/file.js"'</span></code></pre>
<p>A singleton flag passed as a command-line option will override the same flag
passed into <code>NODE_OPTIONS</code>:</p>
<pre><code class="language-bash"><span class="hljs-comment"># The inspector will be available on port 5555</span>
NODE_OPTIONS=<span class="hljs-string">'--inspect=localhost:4444'</span> node --inspect=localhost:5555</code></pre>
<p>A flag that can be passed multiple times will be treated as if its
<code>NODE_OPTIONS</code> instances were passed first, and then its command-line
instances afterwards:</p>
<pre><code class="language-bash">NODE_OPTIONS=<span class="hljs-string">'--require "./a.js"'</span> node --require <span class="hljs-string">"./b.js"</span>
<span class="hljs-comment"># is equivalent to:</span>
node --require <span class="hljs-string">"./a.js"</span> --require <span class="hljs-string">"./b.js"</span></code></pre>
<p>Node.js options that are allowed are:</p>
<!-- node-options-node start -->
<ul>
<li><code>--conditions</code>, <code>-C</code></li>
<li><code>--diagnostic-dir</code></li>
<li><code>--disable-proto</code></li>
<li><code>--dns-result-order</code></li>
<li><code>--enable-fips</code></li>
<li><code>--enable-source-maps</code></li>
<li><code>--experimental-abortcontroller</code></li>
<li><code>--experimental-import-meta-resolve</code></li>
<li><code>--experimental-json-modules</code></li>
<li><code>--experimental-loader</code></li>
<li><code>--experimental-modules</code></li>
<li><code>--experimental-policy</code></li>
<li><code>--experimental-repl-await</code></li>
<li><code>--experimental-specifier-resolution</code></li>
<li><code>--experimental-top-level-await</code></li>
<li><code>--experimental-vm-modules</code></li>
<li><code>--experimental-wasi-unstable-preview1</code></li>
<li><code>--experimental-wasm-modules</code></li>
<li><code>--force-context-aware</code></li>
<li><code>--force-fips</code></li>
<li><code>--frozen-intrinsics</code></li>
<li><code>--heapsnapshot-near-heap-limit</code></li>
<li><code>--heapsnapshot-signal</code></li>
<li><code>--http-parser</code></li>
<li><code>--icu-data-dir</code></li>
<li><code>--input-type</code></li>
<li><code>--insecure-http-parser</code></li>
<li><code>--inspect-brk</code></li>
<li><code>--inspect-port</code>, <code>--debug-port</code></li>
<li><code>--inspect-publish-uid</code></li>
<li><code>--inspect</code></li>
<li><code>--max-http-header-size</code></li>
<li><code>--napi-modules</code></li>
<li><code>--no-addons</code></li>
<li><code>--no-deprecation</code></li>
<li><code>--no-force-async-hooks-checks</code></li>
<li><code>--no-warnings</code></li>
<li><code>--node-memory-debug</code></li>
<li><code>--openssl-config</code></li>
<li><code>--pending-deprecation</code></li>
<li><code>--policy-integrity</code></li>
<li><code>--preserve-symlinks-main</code></li>
<li><code>--preserve-symlinks</code></li>
<li><code>--prof-process</code></li>
<li><code>--redirect-warnings</code></li>
<li><code>--report-compact</code></li>
<li><code>--report-dir</code>, <code>--report-directory</code></li>
<li><code>--report-filename</code></li>
<li><code>--report-on-fatalerror</code></li>
<li><code>--report-on-signal</code></li>
<li><code>--report-signal</code></li>
<li><code>--report-uncaught-exception</code></li>
<li><code>--require</code>, <code>-r</code></li>
<li><code>--throw-deprecation</code></li>
<li><code>--title</code></li>
<li><code>--tls-cipher-list</code></li>
<li><code>--tls-keylog</code></li>
<li><code>--tls-max-v1.2</code></li>
<li><code>--tls-max-v1.3</code></li>
<li><code>--tls-min-v1.0</code></li>
<li><code>--tls-min-v1.1</code></li>
<li><code>--tls-min-v1.2</code></li>
<li><code>--tls-min-v1.3</code></li>
<li><code>--trace-atomics-wait</code></li>
<li><code>--trace-deprecation</code></li>
<li><code>--trace-event-categories</code></li>
<li><code>--trace-event-file-pattern</code></li>
<li><code>--trace-events-enabled</code></li>
<li><code>--trace-exit</code></li>
<li><code>--trace-sigint</code></li>
<li><code>--trace-sync-io</code></li>
<li><code>--trace-tls</code></li>
<li><code>--trace-uncaught</code></li>
<li><code>--trace-warnings</code></li>
<li><code>--track-heap-objects</code></li>
<li><code>--unhandled-rejections</code></li>
<li><code>--use-bundled-ca</code></li>
<li><code>--use-largepages</code></li>
<li><code>--use-openssl-ca</code></li>
<li><code>--v8-pool-size</code></li>
<li><code>--zero-fill-buffers</code></li>
</ul>
<!-- node-options-node end -->
<p>V8 options that are allowed are:</p>
<!-- node-options-v8 start -->
<ul>
<li><code>--abort-on-uncaught-exception</code></li>
<li><code>--disallow-code-generation-from-strings</code></li>
<li><code>--huge-max-old-generation-size</code></li>
<li><code>--interpreted-frames-native-stack</code></li>
<li><code>--jitless</code></li>
<li><code>--max-old-space-size</code></li>
<li><code>--perf-basic-prof-only-functions</code></li>
<li><code>--perf-basic-prof</code></li>
<li><code>--perf-prof-unwinding-info</code></li>
<li><code>--perf-prof</code></li>
<li><code>--stack-trace-limit</code></li>
</ul>
<!-- node-options-v8 end -->
<p><code>--perf-basic-prof-only-functions</code>, <code>--perf-basic-prof</code>,
<code>--perf-prof-unwinding-info</code>, and <code>--perf-prof</code> are only available on Linux.</p>
<h4><code>NODE_PATH=path[:…]</code><span><a class="mark" href="#cli_node_path_path" id="cli_node_path_path">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v0.1.32</span>
</div>
<p><code>':'</code>-separated list of directories prefixed to the module search path.</p>
<p>On Windows, this is a <code>';'</code>-separated list instead.</p>
<h4><code>NODE_PENDING_DEPRECATION=1</code><span><a class="mark" href="#cli_node_pending_deprecation_1" id="cli_node_pending_deprecation_1">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v8.0.0</span>
</div>
<p>When set to <code>1</code>, emit pending deprecation warnings.</p>
<p>Pending deprecations are generally identical to a runtime deprecation with the
notable exception that they are turned <em>off</em> by default and will not be emitted
unless either the <code>--pending-deprecation</code> command-line flag, or the
<code>NODE_PENDING_DEPRECATION=1</code> environment variable, is set. Pending deprecations
are used to provide a kind of selective "early warning" mechanism that
developers may leverage to detect deprecated API usage.</p>
<h4><code>NODE_PENDING_PIPE_INSTANCES=instances</code><span><a class="mark" href="#cli_node_pending_pipe_instances_instances" id="cli_node_pending_pipe_instances_instances">#</a></span></h4>
<p>Set the number of pending pipe instance handles when the pipe server is waiting
for connections. This setting applies to Windows only.</p>
<h4><code>NODE_PRESERVE_SYMLINKS=1</code><span><a class="mark" href="#cli_node_preserve_symlinks_1" id="cli_node_preserve_symlinks_1">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v7.1.0</span>
</div>
<p>When set to <code>1</code>, instructs the module loader to preserve symbolic links when
resolving and caching modules.</p>
<h4><code>NODE_REDIRECT_WARNINGS=file</code><span><a class="mark" href="#cli_node_redirect_warnings_file" id="cli_node_redirect_warnings_file">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v8.0.0</span>
</div>
<p>When set, process warnings will be emitted to the given file instead of
printing to stderr. The file will be created if it does not exist, and will be
appended to if it does. If an error occurs while attempting to write the
warning to the file, the warning will be written to stderr instead. This is
equivalent to using the <code>--redirect-warnings=file</code> command-line flag.</p>
<h4><code>NODE_REPL_HISTORY=file</code><span><a class="mark" href="#cli_node_repl_history_file" id="cli_node_repl_history_file">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v3.0.0</span>
</div>
<p>Path to the file used to store the persistent REPL history. The default path is
<code>~/.node_repl_history</code>, which is overridden by this variable. Setting the value
to an empty string (<code>''</code> or <code>' '</code>) disables persistent REPL history.</p>
<h4><code>NODE_REPL_EXTERNAL_MODULE=file</code><span><a class="mark" href="#cli_node_repl_external_module_file" id="cli_node_repl_external_module_file">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v13.0.0, v12.16.0</span>
</div>
<p>Path to a Node.js module which will be loaded in place of the built-in REPL.
Overriding this value to an empty string (<code>''</code>) will use the built-in REPL.</p>
<h4><code>NODE_SKIP_PLATFORM_CHECK=value</code><span><a class="mark" href="#cli_node_skip_platform_check_value" id="cli_node_skip_platform_check_value">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v14.5.0</span>
</div>
<p>If <code>value</code> equals <code>'1'</code>, the check for a supported platform is skipped during
Node.js startup. Node.js might not execute correctly. Any issues encountered
on unsupported platforms will not be fixed.</p>
<h4><code>NODE_TLS_REJECT_UNAUTHORIZED=value</code><span><a class="mark" href="#cli_node_tls_reject_unauthorized_value" id="cli_node_tls_reject_unauthorized_value">#</a></span></h4>
<p>If <code>value</code> equals <code>'0'</code>, certificate validation is disabled for TLS connections.
This makes TLS, and HTTPS by extension, insecure. The use of this environment
variable is strongly discouraged.</p>
<h4><code>NODE_V8_COVERAGE=dir</code><span><a class="mark" href="#cli_node_v8_coverage_dir" id="cli_node_v8_coverage_dir">#</a></span></h4>
<p>When set, Node.js will begin outputting <a href="https://v8project.blogspot.com/2017/12/javascript-code-coverage.html">V8 JavaScript code coverage</a> and
<a href="https://sourcemaps.info/spec.html">Source Map</a> data to the directory provided as an argument (coverage
information is written as JSON to files with a <code>coverage</code> prefix).</p>
<p><code>NODE_V8_COVERAGE</code> will automatically propagate to subprocesses, making it
easier to instrument applications that call the <code>child_process.spawn()</code> family
of functions. <code>NODE_V8_COVERAGE</code> can be set to an empty string, to prevent
propagation.</p>
<h5>Coverage output<span><a class="mark" href="#cli_coverage_output" id="cli_coverage_output">#</a></span></h5>
<p>Coverage is output as an array of <a href="https://chromedevtools.github.io/devtools-protocol/tot/Profiler#type-ScriptCoverage">ScriptCoverage</a> objects on the top-level
key <code>result</code>:</p>
<pre><code class="language-json"><span class="hljs-punctuation">{</span>
  <span class="hljs-attr">"result"</span><span class="hljs-punctuation">:</span> <span class="hljs-punctuation">[</span>
    <span class="hljs-punctuation">{</span>
      <span class="hljs-attr">"scriptId"</span><span class="hljs-punctuation">:</span> <span class="hljs-string">"67"</span><span class="hljs-punctuation">,</span>
      <span class="hljs-attr">"url"</span><span class="hljs-punctuation">:</span> <span class="hljs-string">"internal/tty.js"</span><span class="hljs-punctuation">,</span>
      <span class="hljs-attr">"functions"</span><span class="hljs-punctuation">:</span> <span class="hljs-punctuation">[</span><span class="hljs-punctuation">]</span>
    <span class="hljs-punctuation">}</span>
  <span class="hljs-punctuation">]</span>
<span class="hljs-punctuation">}</span></code></pre>
<h5>Source map cache<span><a class="mark" href="#cli_source_map_cache" id="cli_source_map_cache">#</a></span></h5>
<p></p><div class="api_stability api_stability_1"><a href="documentation.html#documentation_stability_index">Stability: 1</a> - Experimental</div><p></p>
<p>If found, source map data is appended to the top-level key <code>source-map-cache</code>
on the JSON coverage object.</p>
<p><code>source-map-cache</code> is an object with keys representing the files source maps
were extracted from, and values which include the raw source-map URL
(in the key <code>url</code>), the parsed Source Map v3 information (in the key <code>data</code>),
and the line lengths of the source file (in the key <code>lineLengths</code>).</p>
<pre><code class="language-json"><span class="hljs-punctuation">{</span>
  <span class="hljs-attr">"result"</span><span class="hljs-punctuation">:</span> <span class="hljs-punctuation">[</span>
    <span class="hljs-punctuation">{</span>
      <span class="hljs-attr">"scriptId"</span><span class="hljs-punctuation">:</span> <span class="hljs-string">"68"</span><span class="hljs-punctuation">,</span>
      <span class="hljs-attr">"url"</span><span class="hljs-punctuation">:</span> <span class="hljs-string">"file:///absolute/path/to/source.js"</span><span class="hljs-punctuation">,</span>
      <span class="hljs-attr">"functions"</span><span class="hljs-punctuation">:</span> <span class="hljs-punctuation">[</span><span class="hljs-punctuation">]</span>
    <span class="hljs-punctuation">}</span>
  <span class="hljs-punctuation">]</span><span class="hljs-punctuation">,</span>
  <span class="hljs-attr">"source-map-cache"</span><span class="hljs-punctuation">:</span> <span class="hljs-punctuation">{</span>
    <span class="hljs-attr">"file:///absolute/path/to/source.js"</span><span class="hljs-punctuation">:</span> <span class="hljs-punctuation">{</span>
      <span class="hljs-attr">"url"</span><span class="hljs-punctuation">:</span> <span class="hljs-string">"./path-to-map.json"</span><span class="hljs-punctuation">,</span>
      <span class="hljs-attr">"data"</span><span class="hljs-punctuation">:</span> <span class="hljs-punctuation">{</span>
        <span class="hljs-attr">"version"</span><span class="hljs-punctuation">:</span> <span class="hljs-number">3</span><span class="hljs-punctuation">,</span>
        <span class="hljs-attr">"sources"</span><span class="hljs-punctuation">:</span> <span class="hljs-punctuation">[</span>
          <span class="hljs-string">"file:///absolute/path/to/original.js"</span>
        <span class="hljs-punctuation">]</span><span class="hljs-punctuation">,</span>
        <span class="hljs-attr">"names"</span><span class="hljs-punctuation">:</span> <span class="hljs-punctuation">[</span>
          <span class="hljs-string">"Foo"</span><span class="hljs-punctuation">,</span>
          <span class="hljs-string">"console"</span><span class="hljs-punctuation">,</span>
          <span class="hljs-string">"info"</span>
        <span class="hljs-punctuation">]</span><span class="hljs-punctuation">,</span>
        <span class="hljs-attr">"mappings"</span><span class="hljs-punctuation">:</span> <span class="hljs-string">"MAAMA,IACJC,YAAaC"</span><span class="hljs-punctuation">,</span>
        <span class="hljs-attr">"sourceRoot"</span><span class="hljs-punctuation">:</span> <span class="hljs-string">"./"</span>
      <span class="hljs-punctuation">}</span><span class="hljs-punctuation">,</span>
      <span class="hljs-attr">"lineLengths"</span><span class="hljs-punctuation">:</span> <span class="hljs-punctuation">[</span>
        <span class="hljs-number">13</span><span class="hljs-punctuation">,</span>
        <span class="hljs-number">62</span><span class="hljs-punctuation">,</span>
        <span class="hljs-number">38</span><span class="hljs-punctuation">,</span>
        <span class="hljs-number">27</span>
      <span class="hljs-punctuation">]</span>
    <span class="hljs-punctuation">}</span>
  <span class="hljs-punctuation">}</span>
<span class="hljs-punctuation">}</span></code></pre>
<h4><code>NO_COLOR=&#x3C;any></code><span><a class="mark" href="#cli_no_color_any" id="cli_no_color_any">#</a></span></h4>
<p><a href="https://no-color.org"><code>NO_COLOR</code></a>  is an alias for <code>NODE_DISABLE_COLORS</code>. The value of the
environment variable is arbitrary.</p>
<h4><code>OPENSSL_CONF=file</code><span><a class="mark" href="#cli_openssl_conf_file" id="cli_openssl_conf_file">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v6.11.0</span>
</div>
<p>Load an OpenSSL configuration file on startup. Among other uses, this can be
used to enable FIPS-compliant crypto if Node.js is built with <code>./configure --openssl-fips</code>.</p>
<p>If the <a href="#cli_openssl_config_file"><code>--openssl-config</code></a> command-line option is used, the environment
variable is ignored.</p>
<h4><code>SSL_CERT_DIR=dir</code><span><a class="mark" href="#cli_ssl_cert_dir_dir" id="cli_ssl_cert_dir_dir">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v7.7.0</span>
</div>
<p>If <code>--use-openssl-ca</code> is enabled, this overrides and sets OpenSSL's directory
containing trusted certificates.</p>
<p>Be aware that unless the child environment is explicitly set, this environment
variable will be inherited by any child processes, and if they use OpenSSL, it
may cause them to trust the same CAs as node.</p>
<h4><code>SSL_CERT_FILE=file</code><span><a class="mark" href="#cli_ssl_cert_file_file" id="cli_ssl_cert_file_file">#</a></span></h4>
<div class="api_metadata">
<span>Added in: v7.7.0</span>
</div>
<p>If <code>--use-openssl-ca</code> is enabled, this overrides and sets OpenSSL's file
containing trusted certificates.</p>
<p>Be aware that unless the child environment is explicitly set, this environment
variable will be inherited by any child processes, and if they use OpenSSL, it
may cause them to trust the same CAs as node.</p>
<h4><code>UV_THREADPOOL_SIZE=size</code><span><a class="mark" href="#cli_uv_threadpool_size_size" id="cli_uv_threadpool_size_size">#</a></span></h4>
<p>Set the number of threads used in libuv's threadpool to <code>size</code> threads.</p>
<p>Asynchronous system APIs are used by Node.js whenever possible, but where they
do not exist, libuv's threadpool is used to create asynchronous node APIs based
on synchronous system APIs. Node.js APIs that use the threadpool are:</p>
<ul>
<li>all <code>fs</code> APIs, other than the file watcher APIs and those that are explicitly
synchronous</li>
<li>asynchronous crypto APIs such as <code>crypto.pbkdf2()</code>, <code>crypto.scrypt()</code>,
<code>crypto.randomBytes()</code>, <code>crypto.randomFill()</code>, <code>crypto.generateKeyPair()</code></li>
<li><code>dns.lookup()</code></li>
<li>all <code>zlib</code> APIs, other than those that are explicitly synchronous</li>
</ul>
<p>Because libuv's threadpool has a fixed size, it means that if for whatever
reason any of these APIs takes a long time, other (seemingly unrelated) APIs
that run in libuv's threadpool will experience degraded performance. In order to
mitigate this issue, one potential solution is to increase the size of libuv's
threadpool by setting the <code>'UV_THREADPOOL_SIZE'</code> environment variable to a value
greater than <code>4</code> (its current default value). For more information, see the
<a href="https://docs.libuv.org/en/latest/threadpool.html">libuv threadpool documentation</a>.</p>
</section><section><h3>Useful V8 options<span><a class="mark" href="#cli_useful_v8_options" id="cli_useful_v8_options">#</a></span></h3>
<p>V8 has its own set of CLI options. Any V8 CLI option that is provided to <code>node</code>
will be passed on to V8 to handle. V8's options have <em>no stability guarantee</em>.
The V8 team themselves don't consider them to be part of their formal API,
and reserve the right to change them at any time. Likewise, they are not
covered by the Node.js stability guarantees. Many of the V8
options are of interest only to V8 developers. Despite this, there is a small
set of V8 options that are widely applicable to Node.js, and they are
documented here:</p>
<h4><code>--max-old-space-size=SIZE</code> (in megabytes)<span><a class="mark" href="#cli_max_old_space_size_size_in_megabytes" id="cli_max_old_space_size_size_in_megabytes">#</a></span></h4>
<p>Sets the max memory size of V8's old memory section. As memory
consumption approaches the limit, V8 will spend more time on
garbage collection in an effort to free unused memory.</p>
<p>On a machine with 2GB of memory, consider setting this to
1536 (1.5GB) to leave some memory for other uses and avoid swapping.</p>
<pre><code class="language-console"><span class="hljs-meta">$ </span><span class="language-bash">node --max-old-space-size=1536 index.js</span></code></pre></section>
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